This invention relates generally to sprinkler devices and, more specifically, to rotary sprinkler devices of the pop-up type. These are devices which are designed for in-ground installation typically used in automatic sprinkler systems, and where the sprinkler head moves from a below ground inoperative position, to an above ground operative position in response to the flow of water under pressure.
Rotary sprinklers of the pop-up type are well represented in the patent literature. See for example, U.S. Pat. Nos. Re. 32,386; 3,713,584; 3,724,757; and 3,921,910. In addition, U.S. Pat. No. 3,934,820 describes a rotary pop-up sprinkler which utilizes a gear train to reduce the rotational speed of the rotary nozzle. Reversible, turbine driven sprinkler heads are described in U.S. Pat. Nos. 4,201,344 and 4,624,412. A two-stage pop-up rotary sprinkler is disclosed in U.S. Pat. No. 4,796,809, while the utilization of a viscous brake for controlling nozzle rotation in a pop-up sprinkler is described in U.S. Pat. No. 4,815,662.
Commonly owned prior U.S. Pat. Nos. 4,660,766 and 4,796,811 disclose rotary sprinklers of a non pop-up type which incorporate viscous speed reducing assemblies for slowing the rotational speed of a rotary distributor driven by a water stream discharged from an otherwise stationary nozzle.
The present invention relates to a stream propelled rotary sprinkler of the pop-up type which is characterized by improved performance, simplified construction and lower cost than prior sprinklers of the same or similar type, as explained in greater detail below.